35 Ford drive shaft

Maybe about an 1/8 sticking out. I would assemble the driveshaft into the tube and measure your parts. The driveshaft is positioned by the front bearing.
 
Andy said:
I would assemble the driveshaft into the tube and measure your parts. The driveshaft is positioned by the front bearing.
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Definitely!! Everything hinges on how the parts ALL fit together at the front of the driveshaft / torque tube. Take your driveshaft and assemble it with the speedo gear, the bearing, the washers, everything, into the torque tube and hold it all together with the retaining ring. I have a torque shortened and now I'm facing shortening the driveshaft. I started out with the same question you have now. Came to realize that it's not that simple.
 
I had the drive shaft modified to use a 6 spine pinion, it is all together, and the drive shaft is 5/32 of an inch shy of the end of the bell, the speedo drive has about 3/32 of an inch end play with the lock ring installed. I would like to know if that is ok?. Thanks, Randy
 
You cannot guess at the length of the drive shaft by the spacing at the collar. Because the pinion coupler pin indexes at the pinion shaft hole all measurements must start at that point. The length of the driveshaft is determined by the distance from the lock pin hole in the pinion gear to the forward end of internal spline of the flexible yoke on the u-joint. By using this distance you are matching the driveshaft coupler to coupler pin and the driveshaft will not be too long or too short. By measuring backward from the drive shaft cup you can make the drive shaft too long or to short when the rear coupler is aligned.

Randy since you have already made your drive shaft you will have to install this unit and determine if the speedo turtle matches the driveshaft speedo gear centered. It may be close enough.
 
Dick Spadaro,


When I had the driveshaft modified, it was marked and measured to the center of the safety pin hole. I was looking for some information to double check the driveshaft length. the speedo drive does line up with the drive gear. I will try assembling it to the transmission to check fit before I install it and the transmission. Thanks everyone who replied. Randy
 
Ok, to check that, if you have not shortened your drive shaft the measurement of the shaft should be around 67 1/8" from the center of the pin hole to the snout of the input shaft. This was tape measured off a NOS driveshaft.
 
Randy/In said:
Dick Spadaro,


When I had the driveshaft modified, it was marked and measured to the center of the safety pin hole. I was looking for some information to double check the driveshaft length. the speedo drive does line up with the drive gear. I will try assembling it to the transmission to check fit before I install it and the transmission. Thanks everyone who replied. Randy
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I think you are on the right track.

When I shorten a drive shaft, I make it so when installed, the speedo drive gear will line up in the center of the opening for the speedo driven gear. This is with the speedo drive gear pulled forward against the snap ring. With everything assembled the drive gear needs to have a little for and aft "play" but you may have to use an extra shim between the drive gear and the front drive shaft bearing too keep it from sliding too far back.

I have found most of the time the end of the drive shaft will stick out past the bell apx 1/8 of an inch, however, sometimes they wind up flush and every so often, the end will be about 1/8 inch below flush.

Several CAREFUL measurments and a little math will get you the deminsions you need.

One way to do this is to:

1-Install the drive gear and the snap ring on the drive shaft (gear pulled up against the snap ring).

2-Measure the torque tube from the to the center of the speedo gear opening to the end where it bolts onto the rear end housing.

3-Measure the distance from the center of the retaining pin hole in the pinion to the mating surface of the rear end housing where the torque tube bolts on.

4-Subtract measurment "3" from measurment "2". This is the measurment you need for the distance from the center of the pin retaining hole in the coupling to the center of the speedo drive gear.

This is what I do and it is easy and works well.

I hope this helps,

Chris
 
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